VMware ESXi and vSphere Cluster Management

Delete Virtual Machine Snapshots in VMware vSphere

Learn how Delete and Delete All affect VMware vSphere snapshot trees, delta disks, current VM data, child snapshots, and consolidation.

Purpose of snapshot deletion

In VMware vSphere, delete snapshots from the virtual machine's Snapshot Manager in the vSphere Client. Deleting a snapshot is different from reverting to one: Delete removes a selected restore point while preserving the intended current VM state through disk consolidation.

A snapshot records a point-in-time state. After the snapshot is created, changed virtual disk blocks are written to one or more delta disks instead of directly representing the earlier disk state. When a snapshot is deleted, vSphere commits or reorganizes those changed blocks into another disk state so the remaining chain continues to work.

Deletion is therefore a storage operation, not necessarily an immediate removal of every piece of data associated with the VM's current state. It can take time and generate substantial storage I/O, especially when snapshots are large, old, numerous, or stored on a busy datastore.

Snapshot tree concepts

The base disk is the original virtual disk state. A snapshot is a restore point built on that disk state. A later snapshot is a child snapshot, and the earlier snapshot or disk state on which it depends is its parent snapshot. The VM's active disk state is its current state.

Snapshot Manager displays these relationships as a snapshot tree. The current-state position is commonly marked with text such as You are here. Always identify this marker before choosing a snapshot, because the selected snapshot's position relative to it determines which restore points can remain.

Base disk
  |
 snap01 (parent)
  |
 snap02 (child)
  |
 You are here (current working state)

A branch can be created when a VM is reverted to an earlier snapshot and a new snapshot is then taken. The tree can consequently contain an older path, a current path, and alternate future branches. A snapshot is not a full independent backup of the VM; it depends on its disk chain and datastore files.

Delete one snapshot in Snapshot Manager

  1. Open the target virtual machine in the vSphere Client.
  2. Open Snapshot Manager.
  3. Review the entire tree and locate the You are here current-state indicator.
  4. Select the specific snapshot to remove.
  5. Choose Delete, not Delete All, when only that restore point should be removed.
  6. Review the selected snapshot and its position relative to the current state, then confirm the operation.
  7. Monitor the vSphere task until deletion and any consolidation finish.
  8. Refresh Snapshot Manager and confirm that the selected snapshot is gone and that the expected remaining tree is present.

How the selected snapshot position changes the result

Selected snapshot position       Changed-data handling              Restore-point result
Above current state               Committed to preceding state       Selected point removed; later descendants remain
Current snapshot                  Committed to parent state           Selected point removed; current data remains
Below current-state position      Chain-dependent data reorganized     Dependent later points on that path can be removed
Delete All                         Current path consolidated to base    All snapshot points and alternate branches removed

Deleting a snapshot above the current state

Suppose the tree is Base disk -> snap01 -> snap02 -> current state, and you select snap01. The selected restore point is removed. Its changed data is committed into the preceding disk state, allowing snap02 and the current state to remain usable.

Before:  Base disk -> snap01 -> snap02 -> You are here
Delete snap01
After:   Consolidated preceding state -> snap02 -> You are here

The intermediate restore point is gone, but later snapshots in that branch can remain available.

Deleting the current snapshot

If the selected snapshot corresponds to the current-state position, vSphere commits the changes associated with that snapshot to its parent disk or parent snapshot state. The selected restore point disappears, but the VM keeps its current data after consolidation.

Before:  Base disk -> snap01 -> snap02 (You are here)
Delete snap02
After:   Base disk -> snap01 with snap02's current changes committed

This does not revert the VM to snap01. Reverting would replace the active state with the earlier snapshot state; deleting the current snapshot consolidates the current changes instead.

Deleting a snapshot below the current-state position

A snapshot below the current-state position is on a path whose later history depends on the selected point. Deleting it can remove dependent descendant point-in-time restore points on that path as vSphere reorganizes the chain.

Those discarded snapshot moments cannot be returned to through Snapshot Manager after deletion completes. Inspect the tree carefully before confirmation: a snapshot's visual location, not only its name, determines the outcome.

Delete All behavior

Delete All removes the VM's snapshot hierarchy rather than only one selected restore point. Changes on the path leading to the current state are consolidated into the base disk. Snapshot points on alternate future branches are discarded.

Before:  Base disk -> snap01 -> snap02 -> You are here
                    \-> alternate branch
Delete All
After:   Base disk containing the current disk contents
         No snapshot restore points or alternate branches

The VM retains its current disk contents after the operation, but snapshot-based rollback points no longer exist. Use Delete All only when every snapshot and branch can safely be removed.

Snapshot actions compared

Action       Primary purpose              Current VM data                 Restore points                 Typical use
Delete       Remove one snapshot          Preserved by consolidation       Selected point removed          Remove an obsolete point
Delete All   Remove the whole hierarchy   Current path consolidated         All points and branches gone    Clear all snapshots
Revert       Return to an earlier point   Replaced by selected state        Later changes may be discarded  Roll back deliberately
Consolidate  Finish merging disk data     Consolidated into target state    Cleans remaining delta files     Resolve consolidation need

Safety and operational planning

  • Confirm the VM name, selected snapshot, and current-state marker before confirming.
  • Verify that an independent backup exists if the snapshot is being treated as a recovery point. Snapshots are not a substitute for regular backups.
  • Ensure the datastore has adequate free capacity and healthy storage performance. Consolidation can require temporary working space and sustained I/O.
  • Expect longer operations for large or long-lived snapshots, deep chains, busy VMs, slow datastores, or heavily used storage.
  • Avoid unnecessary VM operations and competing storage-intensive tasks while deletion or consolidation is running.
  • Use descriptive snapshot names and document important recovery points before changing the tree.

Post-deletion verification

  1. Check vSphere task monitoring and wait for the deletion and consolidation task to complete successfully.
  2. Refresh Snapshot Manager and verify that the selected snapshot is absent.
  3. Confirm that the expected remaining snapshots and restore points still exist.
  4. Confirm that the VM is running as expected and that its required disk contents are available.
  5. Check for a reported snapshot or disk-consolidation requirement and use the appropriate vSphere consolidation workflow if one remains.

Troubleshooting snapshot deletion

Deletion takes a long time

Large or long-lived delta disks, high VM write activity, slow or heavily used datastores, and deep snapshot chains can all extend the operation. Allow the task to complete, avoid interrupting it, and review datastore capacity and performance.

The tree or expected snapshot is confusing

You may be viewing a branch rather than the current path, or may not have identified the current-state marker. Start with You are here, then trace parent-child relationships before selecting Delete.

vSphere reports that disk consolidation is needed

This can mean that delta data remains to be merged, a previous operation did not finish, or storage and file-lock conditions prevented cleanup. Review active and recent tasks, confirm free datastore space and storage health, resolve the underlying condition, and then use the appropriate vSphere consolidation workflow.

A needed restore point disappeared

Possible causes include deleting a snapshot below the current position, choosing Delete All, or removing a snapshot with dependent descendants. Snapshot Manager cannot recover a deleted restore point. Use an independent backup if one exists, and require a recovery-point review before future deletions.

Exam-relevant notes

  • Delete removes a selected snapshot; it does not mean revert.
  • Deleting the current snapshot preserves current VM data by committing it to the parent state.
  • Deleting an ancestor can preserve later descendants because its data is consolidated into the preceding state.
  • Deleting below the current position can remove dependent descendant restore points.
  • Delete All removes all snapshot restore points and alternate branches while preserving the VM's current disk contents through consolidation.
  • Snapshot deletion can be I/O-intensive and requires monitoring, datastore capacity, and patience.

For a focused procedure, see Delete a Snapshot.